Blood problems after Sarolaner (Simparica) in dogs

The FDA has received 159 reports of blood problems in dogs after Sarolaner. That is 1.0% of all reports for this medicine, compared with 1.8% across reports for all dog medicines, so it is reported less often than average with this medicine.

159Reports

84%Marked serious

5.0%Recovered

25%Died or euthanised

7 daysTypical onset

How soon it started

Same day

24 18%

1–2 days

22 17%

3–7 days

22 17%

1–4 weeks

28 21%

Over a month

37 28%

How the animals did

Recovered

7 4.4%

Recovered with lasting effects

1 0.6%

Still unwell when reported

102 64%

Died

7 4.4%

Euthanised

33 21%

Not known

9 5.7%

Problems reported at the same time

64 40%

55 35%

41 26%

39 25%

39 25%

29 18%

24 15%

23 14%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Sarolaner kills fleas, ticks and some mites; monthly.

Products with this ingredient include Simparica. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

In 2018 the FDA alerted owners and vets that isoxazoline products have been associated with neurologic reactions such as muscle tremors, wobbliness (ataxia) and seizures, including in animals with no history of them.

Questions owners ask

Can Sarolaner cause blood problems in dogs?: 159 reports link the two, but a report alone does not prove the medicine was the cause: other illnesses, other medicines or coincidence can be involved. Your vet can judge it for your animal.
How soon after a dose was it reported?: In half of the reports with dates, it started within 7 days of the first dose.
What should I do?: Don't give another dose until you've spoken to your vet, and keep the packaging so you can tell them the product and dose. Your vet can also report it to the FDA (or you can, through the manufacturer or FDA form 1932a).

Blood problems with similar medicines

Blood problems after Fluralaner (Bravecto) 634 reports · 0.9% of its reports
Blood problems after Afoxolaner (NexGard) 544 reports · 1.0% of its reports
Blood problems after Lotilaner (Credelio) 125 reports · 1.3% of its reports
Blood problems after Afoxolaner + Moxidectin + Pyrantel (NexGard PLUS) 59 reports · 0.6% of its reports
Blood problems after Lotilaner + Moxidectin + Praziquantel + Pyrantel (Credelio Quattro) 37 reports · 1.2% of its reports

All reported side effects of Sarolaner in dogs · Medicines most reported with blood problems